As equipment that makes use of hard disk devices, opto-magnetic disk devices, optical disk devices, floppy disk devices, and so forth has become smaller and lighter in recent years, there has been an accompanying need for making these devices smaller, thinner, larger in capacity, less costly, and so forth.
For instance, Patent Document 1 (Japanese Laid-Open Patent Application H5-189932 (laid open on Jul. 30, 1993)) discloses a disk device constituted such that the outer periphery of the stator of a spindle motor for driving a disk is surrounded with an iron core, the distance of the outside diameter of the stator from the rotor center is varied with the angle, and the outside diameter in one direction is made smaller than the diameter of the innermost periphery of the disk recording portion.
This allows the head drive actuator to be disposed next to the stator in this one direction, so the head drive actuator can be disposed closer to the center of the disk than in the past, affording a disk drive device that is thinner and more compact.